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(No Model.) 2 Sheets-Sheet 2; A. DAVIDOPF.

ELECTRIC ARC LAMP. v No. 310,124. Patented Dec. 30,1884.

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UNITED STATES PATENT OFFICE.

ALEXIS DAVIDOFF, OF ST. PETERSBURG, RUSSIA, ASSIGNOB TO THEODOREBASILEVSKY, OF SAME PLACE.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 310,12 dated December30, 1884.

Application filed April14, 1884. (No model.) Patented in England March17, 1884, No. 5,026; in France March 18, 1884,1\*o.161,027,- in BelgiumMarch 26, 1884, No..6-l,641,- in Italy June 30, 1884, XVIII, 10,700, andin Austria-Hungary August 29, 1884, No.

11,734 and No. 39,086.

To aZZ whom it may concern:

Be it known that I, ALnxIs Dnvrnorr, of St. Petersburg, Russia, haveinvented certain new and useful Improvements in Electric-Arc Lamps, ofwhich the following is a specification.

This invention has for its object to simplify the construction ofelectric-arc lamps, and to produce a more constant light therefrom.

The accompanying drawings show the construction of the lamp. Figure 1shows a vertical section of the same on line 1 2, Fig. 2. Fig. 2 shows aplan of the lamp, the cover being removed. Fig. 3 shows an end view ofthe circuit-closerin the raised position. Fig. 4 shows an end view ofthe same in the lowered or reversed position.

For the sake of clearness, Fig. 1 shows only one pair of the five pairsof carbons shown in Fig. 2,with the parts belonging thereto. The numberof these carbon pairs can be varied.

Similar parts are indicated by similar letters of reference.

A is the cover or casing inclosing the mech anism of the lamp. B is thebase-plate, of marble, porcelain, &c., on which are fixed the insulatedmetal parts of the lamp. 0 are uprights,which serve, among otherpurposes, as holders for the outer stationary carbons, a. D arecircuit-closers capable of moving to and fro on pivots I) on theuprights O, and having at their upper ends forks c, the hooked ends ofwhich carry short thin pieces of wire (i, which, in bearing against thelower ends of the carbons, hold the circuit-closers in the positionshown. E and E are brackets earrying contact-pieces e and 0, Figs. 2, 3,and 4, which are pressed by means of springs f against the broad ends 9of the circuitcloser, that moves with some friction between them. it aresprings that, when the wire stops (1 are burned through, throw thecircuitclosers D back into their lowest position. (Shown in dotted linesat Fig. 1.) F are uprights carrying the carbon-holders G of the innerearbons, L, such holders being capable of rocking on pivots Z aresetting-screws which pass through the arms at of the carbon-holders, and

sulated from the circuit-closers D.

serve to regulate the inclination of the inner carbons,k,to the outerfixed carbons,c. a are uprights situated upon rods o,screwed into thearms at, and which serve as connterpoises to the carbon-holders G; H,the wire coils of the electro-magnet or solenoid; I, the iron core ofthe same, provided with a disk, p,- J, an upright carrying the axis q ofa double-ended weighted lever, K, the outer end of which carries amovable weight, L, serving to balance the iron core I, which issuspended from the other end of the lever K by the pin 1'; M, a metalring serving as base for all the uprights F, whereby these are all inelectrical connection with each other, and to any point of which the oneend,t,of the coil H is connected by a pinchingscrew, s, the other end ofthe coil, to, being connected by a nut, V, to the extension of the clampN, for the one terminal of the circuit of the dynamo-electric machine,the other terminal of which is held by the clamp O, secured by the nutXV, so as to be in electrical connection with the bracket E. P are metalplates by which the brackets E and E are electrically connected. w is anotch in the disk 9 to enable the screws Z to be conveniently adjusted.

As shown in Figs. 8 and 4, the lower broader part, g, of thecircuit-closers D has a piece of insulating material, 7 .2, let into it,and each of the screws R, Figs. 1 and 2, is in- In consequence whereof,when the circuit-closersDare in the raised position, 3, the electriccurrent cannot pass from the brackets E to the brackets E; but when,owing to the burning of the wire stops (1, the circuit-closers arethrown into the lowest position, Fig. l, the part 9 establishes anelectrical connection between the contact-pieces c and 0, thus enablingthe current to pass from E to E.

The action of the lamp is as follows: Before the lamp is lighted all thecircuit-closers D are in the raised position, being held by the wirestops (Z in electrical contact with the holders 0 of the outer carbons,a. The core I, with its disk p, is also in the raised position, so thatthe upper ends of the carbons a and 7,: are in contact. In lighting thelamp the electric current entering through the clamp 0 passes throughthe bracket E, Fig. 2, contact 0, and circuit-closer D, to the socket Gof the first outer carbon, (1. It then passes through the upper ends ofthe carbons into the inner carbon, 7.:, thence through the upright F,Fig. 1, ring M, and the pinching-screw 8 into the wire tof the coil orsolenoid II, from which i tancc between the points of the carbons a andk is exceedingly small, the electric spark passing across heats the airsituated between them and increases its conductivity; but as soon as thecurrent passing through the coil increases, and the core I isconsequently drawn farther into the coil, the carbon points a and 7.?are moved farther apart, thereby producing the 1 1 hon-holders G for theinner carbons, 7.7, balvoltaic are.

As before stated, the extent of the inclination of the inner pivotedcarbons, 7., to the outer fixed carbons, a, and conseqiiiently theamount of light given by the lamp, can be 1 regulated by the screws Z.

corresponds exactly with all phases of the development of the voltaicare. Great uniformity of the light produced is effected by the perfectbalancing of the carbon-holders G, in consequence whereof the iron coreI and disk p are enabled to move the inner carbons,

The movement of l the carbons a and 7.: to and from each other i 7:, toand from the outer carbons, a, with a very sensitive action, inaccordance with the influence of the electric current; also, by thebalancing of the core I by means of the weighted lever K, any sudden orjerky motion of the core, and consequently of the carbons, is 1 magnetand a series of pairs of fixed and movduccs such an unpleasant effect inmost lamps effectually prevented, which jerky action proof presentconstruction.

have burned down to the point where the wire D will be thrown back bythe spring it into the position shown in dotted lines inI ig. 1.

The electric current then passes from the bracket 1 into the bracket hig. 2, an d thence through the metal plate I to the bracket 1* and 'Whenthe carbons 1 socket O ofthe outer carbon of the next pair, whereuponthis pair of carbons is brought into action in the same manner as abovedescribed, their outer ends having been previously brought into contactby the momentary weakening ot' the current passing through the lamp. Onthe burning down of the second pair of carbons the circuit-closer ofthis pair is also thrown back, and in establishing the electricalcontact with the bracket E of the next pair immediately causes these tobe brought into action, and so on, until the circuit-closer of the lastpairof carbons conducts the current direct to the clamp N. Thus it isonly after all the carbons are consumed that the lamp is extinguishedand cut out of the circuit.

I claim- 1. In an electric-arc lamp, the combination of the fixedcarbon-holder O, and rocking carbon-holder G with a solenoid and itscore I, acting on said rocking holder, and a counterweighted lever, K,supporting the said solenoid core, substantially as set forth.

2. In electric-arc lamps, the combination of the iron core l of theelectro-magnet or solenoid with the disk 1), acting upon the arms in ofthe rocking carbon-holders G of the inner carbons, 7;, for the purposeof moving these away from the outer fixed carbons, a.

3. .ln electric-arc lamps, the rocking caranced by means of weights aton the arms m, and electrically connected by their uprights F, and thering M, carryingthe same, with the one end, 1, of the coil of theelectro-magnet or solenoid.

1-. In clectric-arc lamps, the automatic circuit-closers D, rocking onhorizontal axes, in combination, 011 the one hand, with the uprights Cof the carbon-holders of the outer fixed carbons, a, and with thesprings h, and, on the other hand, both with the brackets ll,

; which conduct the electric current to the outer carbons, a, as alsowith the brackets E, by means of which the electric current is conductedthrough the plate I from the one pair of carbons to the other, or directto the clamp X, leading to the outer circuit.

5. In an electricarc lamp, a central electro name to this specificationin the presence of two subscribing witnesses.

ALEXIS DAVIDOFF.

\Vitnesses:

FREDERIC K. KA If r u, J'umus Hncumxo.

